With the use of more and more internet applications, security becomes more and more important because financial losses caused by hackers and frauds have been significant. By associating the device fingerprints with user behaviors, it may be more efficient to crack fraudulent activities over the internet to protect security. For example, after a mobile phone is assigned a device fingerprint, the mobile phone may be associated with corresponding account information, such that when the account information is used to log in on a device having different device fingerprints, the security of the account may be protected by employing various security measures.